8.2 All Season Native Bee Pests & Diseases

The pests and diseases in this section are attracted to spring mason bee, summer leafcutter bee, and wild bee nesting materials.

Ants

What You See: Lacking wings, a line of ants walk to the nesting holes by crossing the surface the bee house is mounted upon, such as a fence post, wall, or tree.

Effect on Bees: An ant colony may be attracted to the sweet smell of pollen and nectar, bee cocoons, or developing larvae.

What You Can Do: Ants can crawl across double-sided tape, try a stickier product like Tanglefoot or a layer of Vaseline spread along the back of the surface where the bee house is mounted. For a non-toxic solution that does not kill the ants, try our Ant Cant kit, which creates a slippery barrier that ants can't walk across.

Birds

What You See: Nesting holes are strewn on the ground, birds are perching on the edge of the bee house, or you find a bird nest on top of your nesting holes.

Effect on Bees: Nesting birds are attracted to large empty spaces in the bee house. Foraging birds want to eat loose cocoons or peck at filled nesting holes.

What You Can Do: Install bird wire or hardwire cloth with 3/4" openings and loosely create a 3" bubble around the front of the bee house. Do not install the wire flush against the nesting materials because this keeps bees from being able to get in, too. Fill the empty space above the nesting holes or in the attic of your bee house with twigs or crumbled paper to deter birds from nesting.

Spring Mason Bees: As soon as female mason bees are done nesting, remove filled nesting materials from the bee house and protect in a BeeGuard Bag. Store in an unheated and unairconditioned garage or shed over the summer.

Bears

What You See: Nesting trays are on the ground and broken apart, the bee house is on the ground and may be broken

Effect on Bees: Bears are attracted to the sweet smell of pollen, nectar, and bee larvae. Bears can destroy bee houses and take apart the wood nesting trays.

What You Can Do: Move nesting houses out of the bear’s reach, above 8ft high.

Rodents: Rats, Mice, or Squirrels

What You See: Rodents chew apart or leave nibble marks on cardboard BeeTubes and natural reeds. You may find loose nesting holes on the ground.

What You Can Do: When nesting activity is complete, remove nesting holes from the bee house and place capped ends facing up in a chew-proof container made of thick plastic or metal (add a few air holes to the container).

Raccoons

What You See: Wood trays are torn apart or loose nesting holes are on the ground.

Effect on Bees: Raccoons want to eat larvae or adult bees.

What You Can Do: Install the bee house 6’ off the ground.

Earwigs

What You See: Earwigs are skinny insects with pincers on their abdomens. You can find them inside of nesting holes.

Effect on Bees: Earwigs are scavengers that are attracted to pollen, eggs, and developing larvae and they can’t penetrate mud walls. Earwigs are commonly found during bee nesting season and in the fall mason bee cocoon harvest.

What You Can Do: Loosely roll up newspaper, bind it with a rubber band or string, dampen it and place this moisture trap inside the bee house. Dispose of the newspaper and earwigs in your compost pile. Another solution is to build a moat described in the ant section above.

Hornet or Paper Wasps

What You See: You may see the beginning of a paper nest, which looks like an upside-down cup.

Social wasps are not attracted to nesting holes. Wasps that build nests inside of nesting holes are solitary hole-nesting beneficial wasps who are preying on your garden pests.

Effect on Bees: A social hornet or paper wasp queen decides to nest inside the empty space in your bee house.

What You Can Do: Pesticides and chemicals will kill or deter your nesting bees and should be avoided. Wear protective clothing and spray the social wasp nest with high pressure water from a hose. Remove the nesting holes from the bee house or protect from the spray with a piece of cardboard. The best time to spray the social nest is in the late evening. Once removed, add twigs, rocks, or wadded paper to the empty space in the bee house to deter future social wasps. Another option is to let the nest run its course for the season because social wasps build a new nest every year.

Pro Tip: You can also deter social wasps from building nests by installing a fake wasp nest. Inflate a paper bag, cinch the end closed, and hang the paper bag under the eave of your house. Social wasps are territorial and do not want to build nests near each other.